Monthly Archives: November 2014

North America and Pelican Nebula – 2014-10-24

The region around the brightest star Deneb in the constellation Cygnus is occupied by a giant cloud of ionized molecular hydrogen (H II or H2) which is categorized as an “emission nebula”. Three degrees towards the north are two nebula named the “North America Nebula” (NGC 7000) and the “Pelican Nebula” (IC 5070).

NGC7000-IC5070 - North America and Pelican Nebulae - 2014-10-24 v1

NGC7000-IC5070 – North America and Pelican Nebulae – 2014-10-24 v1

The image spans 3.2 x 3.0 degrees which translates to an object size of 96 x 89 ly

The interesting  “North America” shape is caused by interstellar dust blocking some of the light from the nebula. Therefore the stars in the “”Gulf of Mexico” are in front of the dust and closer to us than the actual nebula. The peninsula is referred to as the “Cygnus Wall” and the bright filaments along the wall are regions of intense active star formation.

IC5070 - Pelican Nebula 2014-10-24 v3 high contrast

IC5070 – Pelican Nebula 2014-10-24 v3 high contrast

The Pelican nebula is supposed to look like a pelican taking flight. With the low contrast in my image it’s hard to make out. The pelican is facing towards us and to the left. The top of it’s head is the peak above the bright filament in the upper centre and it’s full beak is pointing down to the left and formed by the cloud along the upper left edge of the nebula. The vertical filament itself outlines the back of the pelican’s neck. The right part of the nebula is then the bird’s right wing on the downward part of a stroke. The left wing would be behind the pelican’s beak.

The pelican shows up better in the high contrast version of just IC 5070 (reprocessed from the same image above).

Generally emission nebula are difficult to see. Although quite large and bright in H-alpha, it is not possible to see this object unaided. The ionized hydrogen glows strongly deep red from the primary Blamer series Hα (hydrogen alpha) at 656nm. Unfortunately our night time vision (scotopic vision) tops out at 620nm, so we cannot see the Hα faint red glow. (Our day time vision – photopic vision – can see deep reds up to about 750nm when they are bright daylight intensities.) But the nebula also glows in other wavelengths so it is possible to see it.

There are some reports that the formation can be seen with binoculars or a small telescope using a UHC filter. I suspect this has to be done under dark skies and ideal conditions. I have never been able to make it out from my semi-rural location.

North America Nebula
– Magnitude: 4.0
– Angular Size: 120 x 100 arc-min
– Distance: 1,600 ly

Pelican Nebula
– Magnitude: 8.0
– Angular Size: 60 x 50 arm-min
– Distance: 1,800 ly

This is a two pane mosaic. The left part of the NA Nebula is from a data set acquired 2010-10-09 using a TV Pronto and Canon XS. The right side of the image, including a good portion of the NA nebula and all of the Pelican Nebula was acquired 2014-10-24 with a Stellarvue 80mm APO and a Canon T2i. The Pronto and SV80 have the same FL of 380mm, but the cameras are different so the image scales of the two sub-frames are different. The Pronto image was up-scaled to match the image scale of the Canon T2i and then aligned and merged to form the composite image.